Simsima eSIM Data Plans for Japan

Simsima does not provide a true unlimited data eSIM for Japan. All the plans that carry “Unlimited” in their name give a fixed high‑speed data allowance of 3 GB per day; after that amount the speed is reduced to 1000 kbps. Consequently, the data is capped rather than unlimited.

If a traveler needs a larger, unthrottled data package, Simsima offers fixed data plans such as the 100 GB plan valid for 180 days (≈ $178.48 USD) and the 50 GB plan valid for 30 days (≈ $34.82 USD). These options provide a higher total data allowance under the same 5G network and do not impose a speed reduction once the data quota is reached.

Simsima does not provide a phone number or SMS capability on its Japan eSIM plans; only data‑only plans are available. Travelers can still use VoIP applications such as WhatsApp, Telegram, and iMessage over the data connection for calls and messaging, but they should check that these services are accessible in Japan before purchasing.

Simsima provides 14 single‑country plans and 21 multi‑country plans for use in Japan. The available plans span a price range from roughly $1.50 to $178.48, with data limits that vary from 100 MB up to 100 GB. The validity of these plans can last anywhere from 5 days to a full year, allowing travelers to choose options that best fit their stay length and data needs.